The present invention relates to a molding plant for chocolate or similar products.
Plants for molding chocolate or suchlike products are known in the prior state of the art, and these plants generally consist of horizontal guides on which the molds, which are generally parallelepipedal in form and have wells into which, for example, the liquid chocolate is to be injected, can be moved.
Along the mold translation guides, which may reach considerable lengths of up to some hundreds of metres, there are cooling devices whose function is to solidify the chocolate in the molds. In addition, the known plant is provided with inverting devices which enable the mold to be rotated through 180.degree. so as to empty it. Devices are also provided for heating the forms, as are knocking units which act directly on the mold. Furthermore the molding plant is generally equipped with devices for cleaning the mold, which after emptying has to be returned to the molding path.
In known molding plants, the conveyance of the molding forms is performed by means of conveying chains that have projecting catches and that run along supporting guides so as to convey the molding forms along the plant.
For some time now the use of chains to move the molding forms has been found to be disadvantageous and complex from the technical point of view. This is because in order to drive ordinary chain conveyors, reducers, transmission shafts, universal joints and advancing mechanisms, having for example a device fitted with a Geneva wheel, are required. The plurality of devices must be distributed along the plant which may be of considerable length, with the result that the assembling and synchronizing of the auxiliary devices and their maintenance constiutes a significant cost.
It has been found that when using chains fitted with catches to move the molds, the speed of advance of the molds cannot be too great because an excessive speed of advance would subject the molds to high accelerations and decelerations, causing the molds to separate from the driving catches and losing the guiding action and the precise geometrical positioning between the catch and the mold, a positioning which has in fact to be maintained rigorously in order to guarantee the reliable operation of the molding plant, which is synchronized with other operating units.
Attempts have been made to overcome in part the problem arising from high acceleration or deceleration by providing runner guides for the molds characterized by a high coefficient of friction, but this requires not only more electrical power but also causes accentuated mechanical wear of the parts involved.
When chains are used for conveying the molds in a molding plant, irregular lengthening of the drive chains is to be observed, due both to thermal expansions that cannot be compensated for and from [sic] normal wear of the chain parts. These lead to imprecise positioning of the molding forms relative to the various operating units connected to the molding line, such as for example the device that fills the wells with the liquid chocolate. The result of this imprecise positioning between the parts is bad production in the form of an imperfectly molded product, or a finished product of poor quality is produced.
Another problem typical of molding plants in which the molds are conveyed by chains is to be seen in the fact that it is essential to lubricate the chains and their drive wheels, and this means that there is a danger of contaminating the product contained in the molds, since the conveying chains are usually located immediately adjacent to the molds containing the product and the lubricant is therefore free to migrate without obstruction along various routes, eventually reaching the chocolate, which will suffer a loss of quality.
Moreover, since each molding plant requires hundreds of metres of drive chain, such a plant will obviously also require continuous adjustments to the members controlling the guide means and synchronizing means because the inevitable lengthening of the chains is prejudicial to their reliable operation and has a negative influence on the entire automation system of the plant.
The presence of chain conveyors in molding plants is a source, furthermore, of soiling and contamination of the entire plant because the chains distribute residues of chocolate around the full extent of the plant.
Owing to the particular technical configuration of a chain, and to the configuration of the various transmission and synchronization members, continuous cleaning operations during the running of the plant in operation are practically impossible. One reason is that in order to recover the not inconsiderable costs of a chocolate molding plant, the plant is used ever more intensively and during more than one shift. Hence to stop the plant for cleaning operations (quite apart from the technical difficulty of carrying out these cleaning operations) would create a serious cost. Last of all, a disadvantage of known plants is the fact that the very long conveying chains suffer, after a period of time, so much wear that the chain has to be replaced, which involves a rather long period of machine stoppage and high costs.
Another disadvantage of molding plants in which the molds are advanced by chains is to be seen in the fact that it is not possible to move the molds conveniently in the different horizontal directions, that is forwards/backwards, left/right, and in the vertical direction, up/down.
This fact makes it very difficult to adapt to changing technological demands resulting from modern molding procedures; moreover, molds with variable dimensions (width/length) cannot be used in known plants without substantial technical modifications to the plant.